Record carrier of the optical type and a device for recording and/or playback for use with such a record carrier

ABSTRACT

The invention relates to a record carrier of a disc-like optically inscribable type, having a preformed track in which an auxiliarily signal comprising a sequence of codes is recorded by means of a preformed track modulation. The codes comprise a sequence of address codes (AC) specifying the addresses of the track portions in which said address codes (AC) are recorded and special codes (SC). The special codes (SC) can be distinguished from said address codes (AC) and specify control data for controlling a recording by a recording device. The sequence can be obtained by replacing in a sequence of address codes (AC) with consecutive address values a plurality of said address by special codes (SC). The periodic pattern of address codes and special codes has a predetermined positional relationship with respect to a predetermined reference address. Such as for example a positional shift with respect to the start of a Lead-in area. The presence and or amount of such a shift may be used to represent additional control information or indicate the presence of area on a disc provided with such additional control information.

FIELD OF THE INVENTION

[0001] The invention relates to a record carrier according to thepre-amble of claim 1. The invention further relates to a deviceaccording to the preamble of claim 6.

BACKGROUND OF THE INVENTION

[0002] Such a record carrier and device are known from the EuropeanPatent EP 0 397 238. The special codes therein comprise specialinformation containing for instance control information for recording,such as write power, location of special areas on the record carrier, areference recording speed, disc application codes, disc type and so on.This has been applied in products commonly known under the name ofrecordable Compact Disc or CD-R. In practice the amount of informationto be stored in the special codes proves to be limited. To solve this,the definition of the special codes could be changed in order to be ableto increase the capacity of information to be stored therein. However,this will result in incompatibility with existing systems and standardspresent on the market.

OBJECT AND SUMMARY OF THE INVENTION

[0003] In consequence, amongst other things, it is an object of theinvention to increase the amount of information to be stored in thespecial codes without changing the definition of the special codes.According to one of its aspects a record carrier according to theinvention is obtained by the characterizing part of claim 1.

[0004] The predetermined positional relation ship may be used, as anexample, to represent specific control information which cannot bestored as special code in the usual manner.

[0005] An advantageous embodiment of a record carrier provided with alead-in area located at an inner area of the disc comprising saidspecial codes, is obtained by the characterizing part of claim 2. Thestart address or end address may be specified in the special informationwhich can be read in advance. This provides a unique reference for eachdisc witch can be used to define a positional relationship.

[0006] A further advantageous embodiment of a record carrier comprisingspecial codes separated by a first number of successive address codes,is obtained by the characterizing part of claim 3. Such a shift isrelatively easy to establish by comparing address codes.

[0007] A next advantageous embodiment of a record carrier comprising afirst number of distinct special codes separated by a first number ofsuccessive address codes is obtained by the characterizing part of claim4. A specific order, for instance of first, second and third specialcode within the periodic pattern, may also easily be detected, as eachspecial code should be uniquely identifiable.

[0008] A further advantageous embodiment of a record carrier providedwith a lead-out area located at an outer area of the disc, is obtainedby the characterizing part of claim 5. This results in an increasedcapacity of storage of additional control information.

[0009] A device for recording and/or playback according to the inventionobtained by the characterizing part of claim 6. Such a device is nowable to detect the presence of a record carrier provided with suchadditional control information and consequently using this information.

[0010] A further advantageous embodiment is obtained by thecharacterizing part of claim 7. Only in case the predeterminedpositional relationship is being detected, a jump of appropriate readingmeans across the record carrier is being performed. The device does needto perform such a time consuming jump if there is no need for, such asfor instance in case of a record carrier without the additionalinformation. Then there will be no performance loss in case of handlingsuch discs.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] These and further aspects and advantages of the invention will bediscussed in more detail hereinafter with reference to the disclosure ofpreferred embodiments, and in particular with reference to the appendedFigures that show:

[0012]FIG. 1 a record carrier provided with a servo-track which exhibitsa track modulation;

[0013]FIG. 2 illustrates a suitable format for an auxiliary signal whichis recorded in the servo track by means of track modulation;

[0014]FIG. 3 gives a code word represented by the auxiliary signal;

[0015]FIG. 4 shows the lay-out of a record carrier;

[0016]FIG. 5 gives a number of bit combinations used in the auxiliarycodes and address codes;

[0017]FIG. 6 shows a possible sequence of successive address codes andspecial codes in the Lead-in area of a record carrier;

[0018]FIG. 7 shows a sequence according to a first embodiment of theinvention comprising a shift with respect to the start of the Lead-inarea;

[0019]FIG. 8 shows a sequence according to a second embodiment of theinvention comprising a specific order of the special codes;

[0020]FIG. 9 shows a sequence according to a third embodiment of theinvention comprising a shift with respect to start of the Lead-in area;

[0021]FIG. 10 shows an embodiment of a recording and/or playback deviceaccording to the invention;

[0022]FIG. 11 shows a flow chart of a control program for controllingthe process of recording information

DESCRIPTION OF THE EMBODIMENTS

[0023]FIG. 1 shows possible embodiments of a record carrier 1 of aninscribable type as described, for example, in the European Patent EP 0325 330 (PHN 12.399). FIG. 1a is a plan view. FIG. 1b shows a small partof a sectional view taken on the line b-b. FIGS. 1c and 1 d are highlyenlarged plan views of a part 2 of a first embodiment and a secondembodiment of the record carrier 1. The record carrier 1 has a track 4,constituted for example by a preformed groove or ridge. The track 4 isintended for recording an information signal. For the purpose ofrecording the record carrier 1 has been provided with a recording layer6 deposited on a transparent substrate 5 and coated with a protectivelayer 7. The recording layer 6 is of a material which, when exposed tosuitable radiation of adequate intensity, is subjected to an opticallydetectable change. Such a layer may be, for example, a thin layer of ametal such as tellurium. By exposure to laser radiation of suitableintensity this metal layer can be melted locally, so that at thislocation said layer will have a different reflection coefficient. Whenthe track 4 is scanned by a radiation beam whose intensity is modulatedin conformity with the information to be recorded an information patternof optically detectable recording marks is obtained, which pattern isrepresentative of the information. The layer may alternatively consistof other radiation—sensitive materials, for example magneto-opticmaterials, a dye, or materials which upon heating are subjected to astructural change, for example from amorphous to crystalline or viceversa. A survey of such materials is given in the book “Principles ofoptical disc systems”, Adam Hilgar Ltd., Bristol and Boston, pp.210-227.

[0024] The track 4 enables a radiation beam which is aimed at the recordcarrier 1 for the purpose of recording the information to be positionedaccurately on the track 4, in other words it enables the position of theradiation beam in a radial direction to be controlled via a trackingsystem employing the radiation reflected from the record carrier 1. Themeasurement system for measuring the radial position of the radiationspot on the record carrier may correspond to one of the systems asdescribed in the above mentioned book “Principles of optical discsystems”.

[0025] The auxiliary signal is recorded in the track 4 by means of apreformed track modulation, suitably in the form of a sinusoidal trackexcursion as shown in FIG. 1c. However, other track modulations such asfor example track width modulation (FIG. 1d) are also suitable. Since atrack excursion is very easy to realise in the manufacture of the recordcarrier it is preferred to use a track modulation in the form of such atrack excursion.

[0026] It is to be noted that FIG. 1 shows the track modulation to ahighly exaggerated scale. In reality it is found that in the case of atrack width of approximately 10⁻⁶ metres an excursion having anamplitude of approximately 30. 10⁻⁹ metres is adequate for a reliabledetection of the scanning beam modulation. An excursion of smallamplitude has the advantage that the distance between adjacent servotracks can be small. FIG. 1 also shows the track pitch (the spacingbetween the track centres) to a substantially larger scale than inreality. In practice the track pitch is approximately 1.6 10⁻⁶ metres.

[0027] An attractive track modulation is that in which the frequency ofthe track modulation is modulated in conformity with the auxiliarysignal. However, other track modulations are also possible.

[0028]FIG. 2 gives an example of a suitable auxiliary signal comprisingcode signals 12 which alternate with synchronising signals 11. Each codesignal 12 may comprise a “biphase-mark” modulated signal having a lengthof 76 channel bits, which signal is representative of a code wordcomprising 38 code bits. In the case of a “biphase-mark” modulatedsignal each code bit is represented by two successive channel bits. Acode bit of a first logic value, in the present example “0”, isrepresented by two bits of the same logic value. The other logic value(“1”) is represented by two channel bits of different logic values.Moreover, the logic value of the “biphase-mark” modulated signal changesafter every pair of channel bits (see FIG. 2), so that the maximumnumber of successive bits of the same logic value is two at the most.The synchronising signals 11 are selected in such a way that they can bedistinguished from the code signals 12. This is achieved when themaximum number of successive bits of the same logic value in thesynchronising signals 11 is selected to be three.

[0029]FIG. 3 shows a suitable format of 38-bit code words 17 representedby the code signals 12. The code word 17 shown therein comprises threebytes 13, 14 and 15 of 8 bits each and a 14-bit group 16. The mostsignificant bits of the bytes 13, 14 and 15 bear the reference numerals20, 21 and 22 respectively. The bytes 13, 14 and 15 are used asinformation bytes and the 14-bit group 16 comprises parity bits for thepurpose of error detection. The values represented by the bytes 13, 14and 15 are referenced mm, ss and ff respectively. Preferably, the 38-bitcode words are recorded in the track at equidistant positions andcomprise address codes AC and special codes SC which can bedistinguished from each other and which are recorded in the track, forexample in the sequence illustrated in FIG. 6.

[0030] In FIG. 6 a constant number, in the present case 9, of addresscodes AC is always followed by an auxiliary code SC. However, it is tobe noted that the number of address codes AC between the auxiliary codesSC may also be variable instead of constant. The address codes maycomprise for example a time code, indicating the time required, when thetrack 4 is scanned at the nominal scanning speed, to bridge the distancebetween a reference position in the track and the location where theaddress code is recorded. Preferably the selected address code is a timecode identical to the absolute time code as included in the subcodeQ-channel during recording of a CD signal. In that case the value mmspecifies a number of minutes and the values ss and ff denote a numberof seconds and a number of frames respectively, the specified number ofseconds varying between 0 and 59 and the specified number of framesvarying between 0 and 74. The number of minutes, seconds and frames mayfor example BCD encoded in the bytes 13, 14 and 15.

[0031] The advantage of the address code described above becomesapparent in particular in the case that a CD signal is to be recorded onthe record carrier. In that case the absolute time code to be includedin the subcode Q-channel can be derived directly from the address codebeing read, as is described in detail in the European Patent EP 0 325330 (PHN 12.399).

[0032] When a standard CD signal is recorded three different areas canbe distinguished on the record carrier, as is illustrated in FIG. 4,namely:

[0033] 1) a program area situated between the radial positions boundedby the radii r2 and r3. In this area the data signals are recorded;

[0034] 2) 2) a Lead-in area situated between the radial positionsbounded by the radii r1 and r2. This area comprises a Lead-in track inwhich the addresses of the different data signals in the program areaare stored in the form of a table of contents, as is described, forexample, in Nederlands Patent Application NL-A-8900766 (PHN 12.887).

[0035] 3) 3) a Lead-out area situated between the radial positionsbounded by the radii r3 and r4. This area comprises a lead-out track inwhich a lead-out signal which can be distinguished from the data signalsis recorded to mark the end of the program area.

[0036] The radial positions of the beginning of the Lead-in area and thebeginning of the program area are prescribed by the CD standard, therequired distance from the beginning of the lead in area to the centreof rotation r0 being 23 mm, while the distance from the beginning of theprogram area to the centre of rotation r0 should be 25 mm. Moreover, thelead-out area is required to begin before a predetermined radialposition.

[0037] For an optimum use of the address code recorded by means of thetrack modulation it is desirable that the values of the address codesrecorded in the track vary identically to the absolute time code in theCD signal to be recorded. This means that the value of the address codein the track portion whose the radial position is indicated by r2 is00:00:00. Preferably the value of the address code in the Lead-in areaincreases to a value 99:59:74 at the end of this area. This has theadvantage that the value 00:00:00 of the first address code in theprogram area directly follows the value 99:59:74 of the last addresscode in the Lead-in area.

[0038] As already stated, it should be possible for the special codesand the address codes to be distinguished from one another. This can beachieved, for example, if the code signals representing the addresscodes and the code signals representing the special codes are precededby different synchronisating signals 11. A number of differentsynchronisation signals 11 which may be used in conjunction with thecode signals 12 described herein are described inter alia in theEuropean Patent No EP 0 342 748 (PHN 12.571).

[0039] However, the special codes can also be distinguished from theaddress codes if the special code contains specific bit combinations inwhich do not occur in the address code. If the time codes describedabove are used for the address codes, this is possible by means of a bitcombination comprising the most significant bits 20, 21 and 22 for thethree bytes 12, 14 and 15, which will be explained with reference toFIG. 5.

[0040] In FIG. 5 the reference numeral 66 denotes the possible bitcombination of the address codes in the Lead-in area. On account of thehigh value mm of the byte 13 in the Lead-in area the most significantbit 20 of the byte 13 in this area will always have the logic value 1.The value ss of the byte 14 varies between 0 and 59, which in the caseof the BCD encoding means that the most significant bit 21 of the byte14 always has the logic value 0. The value ff of the byte 15 variesbetween 0 and 74, so that the most significant bit 22 for the byte 15also always has the logic value 0. The other bits of the bytes 13, 14and 15 in the bit combination 66 may assume either the logic value 0 orthe logic value 1, which is indicated by the symbol “x”.

[0041] The reference numeral 67 denotes the possible bit combinations ofthe bytes 13, 14 and 15 of the address code in the track portionsituated outside the Lead-in area. For the same reasons as in the caseof the address code in the lead in area the most significant bits 21 and22 of the bytes 14 and 15 in the bit combination 67 always have thelogic value 0. Moreover, on account of the limited playing time of therecord carriers address codes having a value for which the mostsignificant bit 20 in the bit combination 67 assumes the value 1 do notoccur in the program area.

[0042] The reference numerals 61, 62, 63, 64, 65 and 69 represent anumber of bit combinations for which the combination of the mostsignificant bits 20, 21 and 22 of the bytes 13, 14 and 15 differ fromthe corresponding bit combinations in the address codes. Therefore thebit combinations may be used for the special codes SC, in which case theseven least significant bits of the bytes 13, 14 and 15 can representadditional information. For example the bit combinations 61 can beemployed to represent the address code of the Lead-in area. Since themost significant bits of the bytes 13, 14 and 15 of the address codesfor the Lead-out area always assume the same logic 0 value, the value ofthe address code for the Lead-out area may be represented completely bythe seven least significant bits of the bytes 13, 14 and 15 in the bitcombination 61.

[0043] Similarly, the value of the address code for the Lead-in area maybe represented by the bit combination 62. The bit combinations 63, 64and 65 can be employed for special codes with which other additionalinformation is recorded in the track, such as for example the writeenergy required for recording, the type of record carrier, the writestrategy etc.

[0044] As can be seen from the definition of a special code as disclosedin FIG. 5, a limited number of bits are available for specialinformation. As such a special code may in practice being incorporatedin a standard, there is no possibility of storing a larger number bytes,as this would effect compatibility with legacy player/recorders. To dealwith this problem, it is possible to use another area of the disc, forinstance the Lead-out area. However, it is not advantageous havingdrives in player/recorders to jump to this area if there is noinformation there, in case of a legacy disc, because of the time thistakes. Therefore, the embodiments according to the invention, solve thisproblem by indicating in the special codes, without effectingcompatibility, either such information or the presence of suchinformation in another area of the disc.

[0045] In practice, the start time of the Lead-in area is indicated insuch a special code, according to existing standards. The frame of theLead-in area will be referred to hereinafter to as SLI. A drive can,when starting up, jump somewhere in the Lead-in area and start readinguntil it recognises special codes. In practice, the discs will startwith a special code SC at SLI, a next special code SC at SLI+10 and soon. However, as current standards prescribe such special code must beused cyclic and must be successively be repeated, the start of such asequence is not being prescribed.

[0046] To put more information of the disc, for instance to indicateavailability of special codes in the Lead-out area, the position of thespecial codes if shifted for n frames, as illustrated in FIG. 7 showinga first embodiment according to the invention of possible address codesand special codes.

[0047] The shift of n frames of a pattern P of one special code SC andnine address codes AC, is defined with respect to the start SLI of theLead-in area. A drive according to the invention, can calculate n bylooking at the differences (in frames) of the found addresses of thespecial codes SC and the start address SLI of the Lead-in area, the lastone being specified in the special codes. Either the amount of such ashift n may indicate additional information to be used by a drive ascontrol information or the the shift may refer to existence of suchinformation elsewhere. Preferably, n is 9 frames in combination with anumber of 9 address codes in a pattern. This additional information maycomprise information with respect to the write strategy of the disc.This may become relevant of high speed discs which require sophisticatedapproaches to write, the definition of such approaches not beingforeseen when defined the format of the special codes.

[0048] Even when an existing disc has such a shift n, a drive accordingto the invention may jump and lose some time, but the system will notfail. There is only a performance problem in such a case. Legacy driveswill not be tempered by the shift n. So this legacy drives can write newdiscs, according to the invention, the old way, due to backwardscompatibility of the old disc and old discs can be written on newdrives, according to the invention, without delay due to the fact thatn=0.

[0049] It is noted that instead of defining a shift with respect to thestart SLI of the Lead-in area, this may alternatively be done withrespect to the end of the Lead-in area or even with respect to the startof the Lead-out area. The shift may thus also being defined backwards.

[0050] An second embodiment according to the invention is shown in FIG.8, where a pattern P comprises an ordered sequence of respectively threedistinct special codes SC1, SC3, and SC2. These distinct special codesbeing individually identifiable, as disclosed with reference to FIG. 5,by bits 20, 21 an 22. As the specific order in a pattern P as such isnot being prescribed by the current standards, this order can be used toencode additional information or the presence thereof.

[0051] A third embodiment according to the invention is shown in FIG.,disclosing a pattern P of special codes SC1, SC2 and SC3 and addresscodes AC, the pattern being shifted with n frames. The special codeswithin in a pattern P may have, or may not have a prescribed order.

[0052] Although it is noted that the invention is described withreference to the current standards for CD-recordable or CD-R, this mayalso be applied to systems with information in a wobble signal, such asCD-rewritable or CD-RW and DVD.

[0053]FIG. 10 shows an embodiment of a recording device for recordingdata signals Vi on the record carrier 1 described above. The recordcarrier 1 is placed on a turntable 80, which is rotated by means of amotor 81. An optical write/read head 82 of a customary type is arrangedopposite the carrier 1 to read and/or record information from/in thetrack 4 by means of a radiation beam 83 which is aimed at the recordinglayer 6. The read head 82 is movable in a radial direction relative tothe record carrier 1 by means of a system which comprises, for example,a motor 85 and a spindle 84. The beam 83 is focused on the recordinglayer 6 in a customary manner and is kept on the track 4 with the aid ofcustomary focusing and tracking systems, not shown. As the track isscanned the beam is modulated in conformity with the preformed trackmodulation. In the read head 82 the beam which is thus modulated isdetected by means of customary radiation-sensitive detectors, whichgenerate signal currents from which a detection signal Vd is derived bymeans of a detection circuit in a manner as described, for example, inthe European Patent EP 0 265 984 (PHN 12.063), frequency of saiddetection signal corresponding to the frequency of the track modulation.The detection signal Vd is applied to a motor control circuit 87 tocontrol the speed of the motor in such a way that the frequency of thedetection signal Vd remains equal to the frequency of a reference clocksignal Ck. The motor control circuit 87 may comprise, for example, aphase detector for detecting the phase difference between the detectionsignal Vd and the reference clock signal Ck, and a power supply circuitfor powering the motor with a voltage whose value depends on the phasedifference thus detected.

[0054] The detection signal Vd is also applied to an FM demodulator 88to recover the auxiliary signal Vh from the detection signal Vd. Therecovered auxiliary signal Vh is applied to a synchronising-signaldetection circuit 89 for detecting the synchronising signals 11 in theauxiliary signal Vh and a “biphase-mark” demodulator 90 for convertingthe auxiliary signals into the 38-bit code words 17. The bits of the38-bit code words 17 are serially applied to an error-detection circuit91, which by means of the parity bits of the bit group 16 determineswhether the code word is received without errors. Moreover, the seriallysupplied code words 17 are applied to serial-parallel converter 92, onwhose output the bits of the bytes 13, 14 and 15 are available inparallel form. The most significant bits 20, 21 and 22 of the 3 bytes13, 14 and 15 applied to the outputs of the converter 92 are fed to acustomary decoder circuit 93, which generates eight signals V1, V2, V3,V4, V5, V6, V7, V8, the relationship between the signals V1, . . . V8and the most significant bits 20, 21 and 22 of the bytes 13, 14 and 15being given in the following Table 1. TABLE 1 MSB 20 21 22 V1 1 0 0 V2 00 0 V3 0 1 0 V4 1 1 0 V5 0 0 1 V6 0 1 1 V7 1 1 1 V8 1 0 1

[0055] The signals V3, V4, V5, V6, V7 and V8 are applied to a controlcircuit 94 for controlling the recording device. The control circuit 94may comprise a microcomputer of a customary type, which is loaded withsuitable control program to be described hereinafter. The signals V1 andV2 on the output of the decoder circuit 93 are applied to a two-input ORgate 95. The signals V1 and V2 indicate that the bytes 13, 14 and 15 onthe output of the converter 92 represent an address code within theLead-in area or an address code outside the Lead-in area, so that theoutput signal of the OR gate 95 always indicates whether the outputsignal of the converter 92 concerns address information. The outputsignal of the OR gate 95 is applied to an input of the two-input ANDgate 96. A signal from the error-detection circuit 90, which signal eachtime indicates by means of a pulse that the received code word 17 iscorrect, is applied to the other input of the AND gate 96.

[0056] Thus, by means of a pulse the AND gate 96 each time indicateswhether the information on the output of the converter represents acorrectly read address code. The output signal of the AND gate 96 isapplied to a parallel load-enable input of a counting circuit 97. Thebytes 13, 14 and 15 appearing on the outputs of the converter 92 areapplied to the parallel inputs of the counting circuit 97, so that uponevery receipt of a correctly read address code the counting circuit 97is loaded with the address code being read. The counting circuit 97 isof a type which in response to a clock pulse on a clock input of thecounter increments the count of the counter by one. A clock signal whichis in synchronism with the synchronisation signals 11 being read isapplied to said clock input, which clock signal is derived from anoutput signal of the synchronising signal detection circuit 89 by meansof a customary phase locked loop circuit 103.

[0057] The counting circuit 97 operates as follows. In response to theclock signal pulses supplied by the phase locked loop circuit 103 thecount is each time incremented by one in synchronism with the operationof reading the code values recorded in the track. This means that assoon as the count has a value corresponding to the address codes beingread the value of the count will follow the values of the address codebeing read regardless of whether the subsequent address codes are readincorrectly or the next code word 17 being read does not contain anaddress code AC but a special code code SC. If at the beginning thecount does not correspond to the address code being read the counter isresponsive to the next pulse on the output of the AND gate 96 to beloaded with the correct value supplied by the converter 92 via itsparallel inputs.

[0058] As long as the count correspond to the address code being readthe pulses on the output of the AND gate will have no effect because thecount then already corresponds to the address code applied to theparallel inputs of the counting circuit. This method of deriving theaddress codes have the advantage that always an address codecorresponding to the position of the track being scanned is available,even in the case that instead of an address code AC an special code SCis recorded in the track. This also means that the track portions inwhich the address codes are recorded remain addressable. The bytes 13,14 and 15 on the output of the converter 92 are applied not only to theparallel inputs of the counting circuit 97 but also to the controlcircuit 94.

[0059] The control circuit will use the information in the special codesto control the recording or reading process. Thereto, the controlcircuit 94 is coupled to the write/read head 82 and the motor 85 viasignal lines 98 and 99. The read head can be set to a read mode or awrite mode via the signal line 98. In the read mode the intensity of theradiation beam 83 remains at a constant small value, which is too smallto bring about the optically detectable change in the recording layer 6.In the write mode the intensity of the radiation beam is switched inaccordance with a write signal Vs between a lower intensity level, whichdoes not bring about an optically detectable change, and a highintensity level (also referred to as write energy), which gives rise toan optically detectable change in the recording layer 6, so that anoptically detectable pattern corresponding to the write signal Vs isformed in the recording layer 6.

[0060] The special code may indicate itself information with respect tothis write signal Vs such as nominal writing power, such as customarywith current standards. However, additional information with respect tomore sophisticated write strategies may be encoded in a manner asdescribed before according to the invention. The control circuitaccording to the invention may comprise there to circuitry in hardwareto detect a shift in the pattern of special codes, the amount of shiftand/or the order of special codes within a pattern of address codes andspecial codes. This may alternatively done by a suitable program loadedin a memory and executed by a processor.

[0061] The write signal Vs is generated by an EFM modulation circuit100, which converts a data signal Vi and the subcode information appliedvia a bus 101 into an EFM modulated signal in conformity with the CDstandard, from which the write signal Vs is derived in a manner asdescribed in detail in, for example, Netherlands Patent ApplicationNL—A-8700934 (PHQ 87.009). Moreover, the high write level (write energy)can be set to a value indicated in the special code.

[0062] The process of recording information on the record carrier iscontrolled by the control circuit 94, which for this purpose is loadedwith a suitable control program. Such a control program may comprise,for example the steps indicated in the flow chart in FIG. 10.

[0063] Step S1 is performed immediately after the record carrier 1 hasbeen loaded into the recording device. In this step S1 the read/writehead 82 is set to the read mode and by means of the signals V3 and V4 onthe output of the decoder circuit 96 it is ascertained whether the codeword supplied to the output of the converter 92 comprises a special codecontaining the address values of the Lead-in or the Lead-out area. Whenthe presence of theses special codes is detected the values of theLead-in area and of the Lead-out area are stored in a memory of thecontrol circuit. 94

[0064] Subsequently, in step S2, the read/write head 82 is directedtowards the track portion containing the address code of the Lead-inarea with the aid of the address code being read. Then the presence andcontent of special codes is being read and stored in the control circuit94. If not special shift and/or order of special codes within thepattern P of address codes and special codes is being detected, writingcontinues as described with reference to step S3, using controlinformation presented by the special codes. However, if such a specialshift and/or order is being detected, the control circuit 94 may eitheruse this information for controlling purpose of may direct theread/write head 82 to a predetermined location, such as for instance theLead-out area for reading additional special codes containing additionalcontrol information,

[0065] In step S3 the read/write head 82 is directed towards a trackportion by means of the address codes being read. When this trackportion is reached the read/write head 82 is set to the write mode,after which the data signal Vi applied to the EFM modulation circuit 100can be recorded. Recording is terminated once the complete data signalto be recorded has been recorded. Upon termination of the recordingprocess step S4 is performed, in which it is ascertained whetherrecording has been discontinued as a result of the track portionspecified by the start address of the Lead-out being reached. If this isthe case, step S5 is performed, in which the lead-out signal is recordedduring a predetermined time interval, the subcode informationcharacterizing the lead-out signal being applied to the EFM modulationcircuit by the control circuit 94. After recording of the lead-outsignal the write/read head 82 is directed towards the lead-in area instep S6 to record the definitive table of contents in the lead-in area.

[0066] If during step S4 it is ascertained that recording of the datasignal has not been discontinued as a result of the track portion havingthe address code with the value AVO being reached, the provisional tableof contents is recorded in the lead-in area during step 57.Subsequently, it is checked in step S8 whether further data signals areto be recorded on the record carrier. If this is the case the program isterminated. If this is not the case, the definitive table of contents isrecorded in the lead-in area in step S9 and the lead out signal isrecorded in step S10, after which the program is terminated.

[0067] In the foregoing the invention has been illustrated for anoptical recording system for recording a standard CD signal on a recordcarrier comprising substantially concentric tracks. However, it is to benoted that the invention equally applies to the recording of signals inlinear tracks. Moreover, the invention may also be applied to therecording of other data signals than CD signals. Neither is the scope ofthe invention limited to optical recording systems. It may equally beapplied to magneto-optical recording systems or magnetic recordingsystems where address codes have been recorded in the track by means ofa previously applied track modulation.

[0068] Finally it is remarked that although he invention has beendescribed with reference to preferred embodiments thereof, it is to beunderstood that these are not limitative examples. Thus, variousmodifications thereof may become apparent to those skilled in the art,without departing from the scope of the invention, as defined by theclaims. For instance a CD-RW may be replaced with a DVD-RW or the like.

[0069] The invention may be implemented by means of both hardware andsoftware, and that several “means” may be represented by the same itemof hardware. Further, the invention lies in each and every novel featureor combination of features. It is also remarked that the word“comprising” does not exclude the presence of other elements or stepsthan those listed in a claim. Any reference signs do not limit the scopeof the claims.

1. A record carrier of the disc-like optically inscribable type, havinga preformed track in which an auxiliarily signal comprising a sequenceof codes is recorded by means of a preformed track modulation, whichcodes comprise a sequence of address codes (AC) specifying the addressesof the track portions in which said address codes (AC) are recorded andspecial codes (SC) which can be distinguished from said address codes(AC) specifying control data for controlling a recording by a recordingdevice and which sequence can be obtained by replacing in a sequence ofaddress codes (AC) with consecutive address values a plurality of saidaddress by special codes (SC), characterized in that, the said sequencecomprises a periodic pattern of address codes and special codes whichpattern has a predetermined positional relationship with respect to apredetermined reference address.
 2. Record carrier according to claim 1,provided with a lead-in area located at an inner area of the disccomprising said special codes, characterized in that, the predeterminedreference address is the start address or end address of the lead-inarea.
 3. Record carrier according to claim 2, the periodic patterncomprising special codes separated by a first number of successiveaddress codes, characterized in that, the periodic pattern is shifted apredetermined number of address codes with respect to the predeterminedreference address.
 4. Record carrier according to claim 2, the periodicpattern comprising a first number of distinct special codes separated bya first number of successive address codes, characterized in that, thefirst number of distinct special codes have a predetermined order. 5.Record carrier according to claim 2, provided with a lead-out arealocated at an outer area of the disc, characterized, in that thelead-out area comprises additional control information for controllingrecording by a recording device, the presence thereof being indicated bythe predetermined positional relationship.
 6. Device for recordingand/or playback a record carrier of the inscribable type as claimed inany one of the claim 1-5, the device comprising reading means forreading the information recorded on the record carrier and recordingmeans for recording the record carrier in accordance with an recordingprocess, the reading means comprising means to read the auxiliary signalrecorded on a record carrier, selecting means for selectively selectingextracting the special codes and the address codes from the auxiliarysignal, control means for controlling the recording process,characterized in that, the control means are adapted to determine thepredetermined positional relationship of the periodic pattern of addresscodes and special codes and to control the recording process inaccordance with said determination.
 7. Device according to claim 6,characterized in that, the control means are adapted to read a specialarea on the record carrier upon detecting a predetermined positionalrelationship.
 8. Device according to claim 7, adapted to cooperate witha record carrier provided with a lead-in zone at an inner part of therecord carrier and a lead-out zone at an outer part of the recordcarrier, characterized in that, the control means are adapted toinitially read the special information in the lead-in zone and, onlyupon detection of a predetermined positional relationship, subsequentlyread the lead-out zone